With the progress of modern society, attention on significance of personal identity identification and personal information security is gradually increasing. Due to uniqueness and invariance of human fingerprints, fingerprint recognition technology has high security and high reliability, and is simple and convenient to use. As a result, fingerprint recognition technology is widely applied to various fields of personal information security protection. With the continuous developments in science and technology, information security problem of various electronic products is always one of the focus points in technology development. Especially for mobile terminals such as mobile phone, laptop computer, tablet computer and digital camera, a requirement for information security is more urgent.
A conventional fingerprint recognition device may implement sensing in a capacitive (electrical field) manner or in an inductive manner. The fingerprint recognition device obtains fingerprint information of a user by extracting a fingerprint of the user and converting the fingerprint of the user into an electrical signal for outputting. Specifically, reference is made to FIG. 1, which is a schematic sectional view of a conventional fingerprint recognition device. The fingerprint recognition device includes a substrate 100, a fingerprint recognition chip 101 coupled to a surface of the substrate 100, and a glass substrate 102 covering a surface of the fingerprint recognition chip 101.
A capacitive fingerprint recognition chip is taken as an example. The fingerprint recognition chip 101 includes one or more capacitor plates. An epidermis or a subcutaneous layer of a finger of the user includes raised ridges and depressed valleys, and distances between the ridges and the fingerprint recognition chip 101 are different from those between the valleys and the fingerprint recognition chip 101 when the finger 103 of the user touches a surface of the glass substrate 102. Therefore, capacitance values between the ridges of the finger 103 of the user and the capacitor plates are different from those between the valleys of the finger 103 of the user and the capacitor plates. The fingerprint recognition chip 101 can obtain the different capacitance values, convert the capacitance values into corresponding electrical signals and output the electrical signals. The fingerprint recognition device can obtain fingerprint information of the user after collecting the received electrical signals.
In practice, a conventional fingerprint recognition device has a high requirement on sensitivity of a fingerprint recognition chip, which limits manufacture and application of the fingerprint recognition device.